Process of making explosive powder.



CHARLES HERBERT COY, OF BOSTON, MASSACHUSETTS.

PROCESS OF MAKING EXPLOSIVE POWDER.

SPECIFICATION forming part of Letters Eatent No. 681,908, datedSeptember 3, 1901.

Application filed October 10, 1900- Serial No. 32,561. (No specimens.)

To all who-721, it may concern:

Be it known that 1, CHARLES HERBERT COY, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Processes of Making Explosive Powder, of which thefollowing is a specification.

This invention has for its object the production of a powder which willnot explode unless confined and held under pressure, but when properlyconfined in a hole drilled in rock, coal, or slate or back of aprojectile in a rifled barrel will explode with great force.

The invention also has for its object to pro- 'duce a semi smokeless,fiameless, and odorless powder, these qualities being eminentlydesirable in powder used in mines of mineral and coal and in stone andslate quarries, because there is no flame to ignite pit-gases and nonoxious fumes and gases to prevent workmen from entering mines ortunnels immediately after a blast, the powder being comparatively safeinmanufacturing, handling, transportation, and storage, because it isnon-explosive when unconfined.

My powder is a combination of a highlygaseous bituminous coal low inforeign and earthy substances, nit-rate of sodium, and sulfur, treatedduring the process of manufacture with a volatile hydrocarbon and withboiling water, as hereinafter described.

The specific materials used in the process and the proportions that makethe most perfect powder known to me are as follows: seventy and one-halfper cent. nitrate of sodium,

'fifteen and one-half per cent. highly-gaseous bituminous coalcontaining from thirty to forty per cent. of volatile matter, twelve andthree-fourths per cent. sulfur, one and threefourths per cent.hydrocarbon, preferably gasolene, and three gallons, more or less, ofboiling water.

I have demonstrated by my various experiments and tests that acommercial volatile hydrocarbon is a useful incorporating agent inadmixing nitrate of sodium, gaseous bituminous coal, and sulfur andcauses the combination to become more easily a homogeneous mixture. Uponsubsequent treatment in the manner specified below the bulk of thehydrocarbon becomes evaporated, leaving a residue, which acts as abinder, giving great cohesive strength to the cakes when subjected tohydraulic pressure of four thousand pounds per square inch, this beingessential in finishing and graining the powder to be graded and inkeeping it from deterioration and cakiug.

My process hereinafter described produces a powder that has a finishedgrain of cohesive strength and that can be graded to various sizes,giving all the various grades required to meet the commercial demandsfor a powder that will not cake or deterioratein time.

In describing my process,and assuming that a batch of three hundredpounds is to be made, I take two hundred and eleven and onehalf poundsnitrate of sodium and forty-six and one-half pounds bituminous coal,each previously reduced to an impalpable powder in a suitablepulverizing apparatus and then transferred to a mixer, where it isthoroughly 7 mixed. To the mixture I add one-half gallon of volatilehydrocarbon, preferably gasolene. When the hydrocarbon is fullyincorporated into the mixture, the whole is transferred to a suitablesteam-jacketed mill or equivalent apparatus, heated as hot as possiblewith live steam, the mixture being spread evenly over the heated bottomof the mill. While the mill is in operation I add from two to threegallons of boiling water, which causes an intimate mixture or unionbetween the nitrate and coal-dust. Under some circumstances anadditional quantity of boiling water may be required. After the mill hasrun twenty minutes I add thirtyeight and one-fourth pounds of sulfurpreviously pulverized and continue running the mill for forty minuteslonger until the mixture assumes a dark-brown color and is as dry as itis possible to make it without the wheel cutting through onto the bed. Ase ries of carefully-conducted experiments and tests have proved beyonda question of doubt that the mixing apparatus should only be used formixing the nitrate of sodium and the carbon. If sulfur is added beforethe soda and carbon are incorporated together, the product will be muchinferior. This process insures a thorough mechanical mixture of all theingredients, the entire mass being homogeneous and ready for pressinginto cakes. The mass or compound is then transferred to a hydraulicpress, where it is subjected to a pressure not to exceed four thousandpounds per square inch, and thus formed into cakes. These cakes aretaken to a corning-mill and there grained, the dust being removed fromthe grains by a suitable screen attachment. The grained powder is thendried in a dryinguoom, the air of which is maintained at a temperatureof 175, and allowed to remain there for ten hours, and is then glazed inany suitable revolving glazing-barrel. After the barrel has'run forfourhours there is added a small quantity of the best graphite, and thebarrel is run for six hours longer. From the glazing-barrel the grainedpowder goes to a sizing-mill, which assorts the various grades from fuseor dust powder to O. F., the coarsest grade, thus completing theoperation of making a perfectly glazed, grained, and graded powder thatwill maintain its form and will not cake or deteriorate in time, asvarious kinds of black powder do.

gredients to more readily unite before the addition of boiling water andsulfur. This softening effect is apparent throughout the subsequentsteps of the process and assists particularly in the pressing operation,giving the particles greater adhesiveness to each The volatile hy-.drocarbon has a softening effect on the pulverized bituminous coal,enabling said in riods of time Without deterioration 011 account ofmoisture. This quality of the powder is due in part to the elfect of thevolatile hydrocarbon.

' I claime- 1. That improvement in the process of making explosivepowder, which consists in first mixing nitrate of sodium and carbon,then adding a volatile hydrocarbon thereto, and then heating themixture.

2. That improvementin the process of making explosive powder, whichconsists in first mixing nitrate of sodium and carbon, then adding avolatile hydrocarbon thereto, then heating the mixture and trituratingit while it is heated.

3; That improvement in the process of making explosive powder, whichconsists in first mixing nitrate of sodium, then adding a volatilehydrocarbon thereto, and then simultaneously heating and triturating themixture, and at the same time adding boiling water thereto.

4. Thatimprovement in the process of making explosive powder, whichconsists in first mixing nitrate of sodium and carbon, then adding avolatile hydrocarbon thereto, then adding boiling water to the mixture,then simultaneously heating and triturating, and

then adding sulfur and additionally triturating.

In testimony whereof I have affixed my signature in presence of twowitnesses.

CHARLES HERBERT COY. NVitnesses:

C. F. BROWN, A. D. HARRISON.

